I'm sorry i haven't done that. But i didn't want your post to sit empty because it is a valid question...so i'm giving it a bump up in hopes someone will answer with experience.
Have Safe Travel and Make Lots of Wonderful Memories!
Not from Embassy suites, but rather from a different property, I had no problem with the ART system, all of their routes begin and terminate at Dl.
Passes are available, for example, a 3 day pass is but $8.00, otherwise the cost is $3.00 per day. I rode ART each day, for 3 days in total, and never once had to wait more than a few minutes if even that, for it to arrive, even when I had just missed my connection at Dl. to go back to my property, in less than 10 minutes, it was back.
Just remember which route that you need to take, and in the early afternoon, the drivers and their red buses, take a lunch break, in August, it was between 1 - 2 p.m., and that is probably a standard time, regardless of which season one may be in Anaheim.
ART has a website, and a paper schedule as well available, the drivers are very well informed too, and they will let you know whatever it may be that you may have a question regarding your travel with them, and in the area, they will also tell you about their lunch break time, and what times are best for returning after the park closes, so as to not miss the last ART.